I can't see any difference in https://www.amazon.com/SUNPOW-Resistance-Assistance-Exercise-Powerlifting/dp/B07K1823XB/ref=mp_s_a_1_8?keywords=layered+resistance+bands+natural+latex&qid=1675615430&refresh=1&sr=8-8 and https://www.amazon.com/Undersun-Fitness-Latex-Exercise-Resistance/dp/B07DZXTCCM/ref=mp_s_a_1_3?keywords=layered+resistance+bands+natural+latex&qid=1675615430&refresh=1&sr=8-3
Prices are being gouged right now, unfortunately. I got this set a week or so ago and I really like them, but now they're $5 higher. Usually these go for $30ish.
There's also this set for $5 more, but it comes with an extra band and a higher resistance overall. I prob would have gotten these had they been in stock at the time.
Otherwise you can get them directly from China on AliExpress for $25-$30 or so, but it'll take a few weeks to get them
I personally use Sunpow from Amazon. Unfortunately due to the current climate we're in, it's sold out but any similar brand should do the same thing.